On July 5, 2012, the buzz of André Borschberg’s cell phone pulled him out of a meeting at a military airfield northeast of Lausanne, Switzerland. The news wasn’t good. The former Swiss Air Force pilot rushed to his helicopter and raced the familiar 45-minute route to Dübendorf, near Zurich.
After touching down at the helipad, he sprinted to the cavernous hangar and swung open its blue door to find the splintered remains of a critical piece of his latest engineering endeavor: part of the 236-foot-long carbon fiber wing of a solar plane designed to circumnavigate the globe. A team of 40 engineers had spent nine months designing this wing, another nine months building it, and the past four weeks testing it. In a final round of tests, the team had hung an elaborate wooden framework and up to 6 tons of lead weights off the spine of the wing — known as the wing spar — to simulate the stress of the forces the plane could experience during heavy turbulence. Because of a mistake in the design, the spar had buckled.
The plane, christened Solar Impulse 2 (the first Solar Impulse was a prototype), has been 10 years and about $150 million in the making. Next year, Borschberg and project partner Bertrand Piccard plan to fly the plane around the world, taking turns on four- to five-day hops over the course of three or four months. But that’s assuming the plane is ready by then.
Seeing the mangled wing felt like “a big hit in the stomach,” Borschberg says. But his confidence didn’t waver; he’s not the kind of guy to let disappointment slow him down. And soon, he would entrust his life to this futuristic flyer. With the 2015 takeoff date looming, the Solar Impulse engineers went back to the drawing board, finally deciding on a design that added a bit of weight to get a wing that could weather the challenges in store.
